KCNK9 and sleep apnea syndrome: However, a clear mechanistic link between TASK-1 and sleep apnea remains unproven and is further complicated by the propensity of TASK-1 subunits to co-assemble with related TASK-3 (KCNK9) subunits to form new heteromeric TASK-1–TASK-3 channels in cells where both genes are coexpressed25,26.